Efficacy of cap-assisted endoscopy for routine examining the ampulla of Vater

Figure 1 Endoscopic transparent cap. A: Short transparent cap (Olympus distal attachment D-201-10704, outer diameter: 11.35 mm, length from distal end of endoscope: 4 mm; Olympus Tokyo, Japan); B: Long transparent cap (Olympus distal attachment MH-593, outer diameter: 12.9 mm, length from distal end of endoscope: 11 mm; Olympus); C: Short cap attached to the tip of a forward-viewing endoscope; D: Long cap attached to the tip of a forward-viewing endoscope.

Figure 2 Flow diagram of patient enrollment and examinations. In total, 120 patients were examined by forward-viewing endoscopy. In cases when complete observations of the ampulla of Vater (AV) were unsuccessful, an additional examination for the AV was conducted by short cap-assisted endoscopy. If that examination was unsuccessful, the short cap was replaced with a long cap, and a re-examination was performed.

Figure 3 Outcomes of conventional endoscopy. A: Complete observation of the ampulla of Vater (AV), including the orifice, by forward-viewing endoscopy; B: Partial observation of the AV with a folded mucous membrane by forward-viewing endoscopy; C: The AV was not found during forward-viewing endoscopy.

Figure 4 Incomplete observation of the ampulla of Vater by conventional endoscopy and outcomes of cap-assisted endoscopy. A: Incomplete observation of the ampulla of Vater (AV) by forward-viewing endoscopy due to a folded mucous membrane; C: Incomplete observation of the AV due to the close proximity of the endoscope tip to a superior ampulla lesion; E: Incomplete observations of the AV on the edge of diverticulum; B, D, F: Complete observation of the AV, including the orifice, by short cap-assisted endoscopy (A→B, C→D, E→F); G: Incomplete observation of the AV by short cap-assisted endoscopy due to a loop in the scope; H: Complete observation of the AV by long cap-assisted endoscopy (G→H).